Hi there, Not sure exactly, but I am thinking along the lines of ; If you stray from the given track by more than xxx distance (maybe the user can change this in settings) then, take the current GPS position and calculate a new route to the destination. Some notification that a new route is being calculated would be good. This is often useful if for example there is heavy traffic and you want to take another route, or if there is a road closure. Hope you can implement this function. Your application is getting better and better and the frequent updates are really positive. Mike